128 lines · cpp
1//===- StringToOffsetTable.cpp - Emit a big concatenated string -*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "llvm/TableGen/StringToOffsetTable.h"10#include "llvm/Support/FormatVariadic.h"11#include "llvm/Support/raw_ostream.h"12#include "llvm/TableGen/Error.h"13#include "llvm/TableGen/Main.h"14 15using namespace llvm;16 17unsigned StringToOffsetTable::GetOrAddStringOffset(StringRef Str) {18 auto [II, Inserted] = StringOffset.insert({Str, size()});19 if (Inserted) {20 // Add the string to the aggregate if this is the first time found.21 AggregateString.append(Str.begin(), Str.end());22 if (AppendZero)23 AggregateString += '\0';24 }25 26 return II->second;27}28 29void StringToOffsetTable::EmitStringTableDef(raw_ostream &OS,30 const Twine &Name) const {31 // This generates a `llvm::StringTable` which expects that entries are null32 // terminated. So fail with an error if `AppendZero` is false.33 if (!AppendZero)34 PrintFatalError("llvm::StringTable requires null terminated strings");35 36 OS << formatv(R"(37#ifdef __GNUC__38#pragma GCC diagnostic push39#pragma GCC diagnostic ignored "-Woverlength-strings"40#endif41{} constexpr char {}{}Storage[] =)",42 ClassPrefix.empty() ? "static" : "",43 UsePrefixForStorageMember ? ClassPrefix : "", Name);44 45 // MSVC silently miscompiles string literals longer than 64k in some46 // circumstances. The build system sets EmitLongStrLiterals to false when it47 // detects that it is targetting MSVC. When that option is false and the48 // string table is longer than 64k, emit it as an array of character49 // literals.50 bool UseChars = !EmitLongStrLiterals && AggregateString.size() > (64 * 1024);51 OS << (UseChars ? "{\n" : "\n");52 53 ListSeparator LineSep(UseChars ? ",\n" : "\n");54 SmallVector<StringRef> Strings(split(AggregateString, '\0'));55 // We should always have an empty string at the start, and because these are56 // null terminators rather than separators, we'll have one at the end as57 // well. Skip the end one.58 assert(Strings.front().empty() && "Expected empty initial string!");59 assert(Strings.back().empty() &&60 "Expected empty string at the end due to terminators!");61 Strings.pop_back();62 for (StringRef Str : Strings) {63 OS << LineSep << " ";64 // If we can, just emit this as a string literal to be concatenated.65 if (!UseChars) {66 OS << "\"";67 OS.write_escaped(Str);68 OS << "\\0\"";69 continue;70 }71 72 ListSeparator CharSep(", ");73 for (char C : Str) {74 OS << CharSep << "'";75 OS.write_escaped(StringRef(&C, 1));76 OS << "'";77 }78 OS << CharSep << "'\\0'";79 }80 OS << LineSep << (UseChars ? "};" : " ;");81 82 OS << formatv(R"(83#ifdef __GNUC__84#pragma GCC diagnostic pop85#endif86 87{1} llvm::StringTable88{2}{0} = {0}Storage;89)",90 Name, ClassPrefix.empty() ? "static constexpr" : "const",91 ClassPrefix);92}93 94void StringToOffsetTable::EmitString(raw_ostream &O) const {95 // Escape the string.96 SmallString<256> EscapedStr;97 raw_svector_ostream(EscapedStr).write_escaped(AggregateString);98 99 O << " \"";100 unsigned CharsPrinted = 0;101 for (unsigned i = 0, e = EscapedStr.size(); i != e; ++i) {102 if (CharsPrinted > 70) {103 O << "\"\n \"";104 CharsPrinted = 0;105 }106 O << EscapedStr[i];107 ++CharsPrinted;108 109 // Print escape sequences all together.110 if (EscapedStr[i] != '\\')111 continue;112 113 assert(i + 1 < EscapedStr.size() && "Incomplete escape sequence!");114 if (isDigit(EscapedStr[i + 1])) {115 assert(isDigit(EscapedStr[i + 2]) && isDigit(EscapedStr[i + 3]) &&116 "Expected 3 digit octal escape!");117 O << EscapedStr[++i];118 O << EscapedStr[++i];119 O << EscapedStr[++i];120 CharsPrinted += 3;121 } else {122 O << EscapedStr[++i];123 ++CharsPrinted;124 }125 }126 O << "\"";127}128